METHOD OF MANUFACTURING HELICAL CYLINDRICAL SPRINGS Russian patent published in 2019 - IPC B21F35/00 

FIELD: machine building.

SUBSTANCE: invention relates to machine building and can be used in making helical compression cylindrical springs. Method includes winding of spring with pitch exceeding that of finished spring, heat treatment, lumocontrol, shot blasting and grinding of spring ends. At the final stage, the outer and inner surfaces of the spring are cold-formed, which is performed by expanding the spring turns to the surface of the matrix hole by the male die, and cold-hardening of spring surface along contact line of turns to each other by means of hardening device when spring is located in die hole, which is performed in process of plastic deformation of spring at expansion of turns by male die due to applied axial force, wherein said operation is performed with spring free ends that are not secured in tangential direction and have free rotation possibility.

EFFECT: higher efficiency of spring manufacture and stability of elastic properties of reinforced spring.

1 cl, 1 dwg